In the United Kingdom, food allergies impact 6-8% of young children and approximately 1-2% of adults, and have a considerable influence on the overall quality of life for affected families.
Here, Allergy London’s Paediatric allergist, Professor Adam Fox, shares crucial insights to unravel the complexities surrounding food allergies. This blog is focused on clarifying what a food allergy is and key aspects that contribute to a foundational understanding of food allergies.
What is a food allergy?
- A food allergy manifests as an inappropriate over-sensitivity to specific food proteins, such as those found in milk, eggs, or particular nuts.
- Exposure to the allergen triggers the release of chemicals in the body, notably histamine, leading to unpleasant and potentially harmful effects. The most severe reaction, known as anaphylaxis, can be life-threatening.
- Some food allergies, often termed delayed or non-IgE mediated, involve a slower-acting part of the immune system. While these reactions can be unpleasant, they are typically not dangerous and primarily affect infants, often being outgrown in early childhood.
- Accurate identification of problematic foods is crucial for optimal management. Patients should be well-informed on recognising and treating allergic reactions. Additionally, it is vital to identify and address common issues like eczema and asthma, which frequently coexist with food allergies.
- While certain childhood food allergies, such as those related to milk, eggs, and wheat, often resolve as the child grows, others like nuts, sesame, fish, and shellfish allergies may persist into adulthood.
- Any concerning symptoms should be discussed with a healthcare Professional such as an Allergist or general practitioner (GP) as the first step. GPs can refer individuals, if necessary, to a children’s allergy specialist for comprehensive management and care.
Which foods commonly trigger allergies in people?
Most individuals with food allergies react to a limited range of items. The primary allergen is often eggs, with other prevalent triggers including milk, nuts, sesame, fish, shellfish, wheat, soy, and kiwi. The specific foods causing allergies can vary based on the dietary patterns within a family and may differ across regions globally.
Delayed food allergies:
For delayed food allergies, particularly observed in younger children, distinctive challenges arise, making diagnosis challenging. Such symptoms, which are very common in children without food allergies, warrant consideration for allergy only if they are multiple, severe, persistent, and resistant to treatment.
These symptoms may include:
- Gastroesophageal reflux (effortless vomiting, usually after feeds)
- Poor weight gain
Unless the underlying allergy is identified and eliminated, symptoms may persist and intensify despite the aggressive use of treatments like steroids or other medications. However, delayed food allergy is rare and overdiagnosis can commonly occur.
Food allergies can emerge in adults as a newfound issue or may persist from childhood allergies. While certain childhood allergies, especially to milk, eggs, and wheat, may resolve over time, others, such as allergies to nuts, sesame, fish, and shellfish, may persist.
What are the indications and symptoms of a food allergy?
Typical symptoms associated with food allergies include the below mild reactions
- Itchy rash/hives
- Runny eyes and nose
- Abdominal pain, diarrhoea, and vomiting
Symptoms typically appear quickly after ingestion of the food causing the problem. Mild reactions also include swollen lips; the right thing to do if there of symptoms of this or itchy rash/hives is to give antihistamines and keep a close eye.
Recognising severe reactions
In more severe instances, food allergies can lead to:
- Breathing difficulties (shortness of breath)
- Circulatory issues resulting in dizziness and collapse due to low blood pressure
- Persistent cough
The above are symptoms of a severe allergic reaction, Anaphylaxis, which is a medical emergency. If there is any suggestion that your child’s Airway, Breathing or Consciousness is involved then if you have been prescribed an Adrenaline autoinjector (AAI), use it immediately – this is a sign of Anaphylaxis, a severe allergic reaction; it’s important to use AAIs at the first sign of Anaphylaxis or if in doubt.
The approach to take in the event of Anaphylaxis (or if in doubt):
- Lie the person down or if more comfortable sit them up:
- Administer adrenaline in the upper thigh muscle.
- Call 999 (or emergency services) and mention anaphylaxis.
- If symptoms don’t improve within 5 minutes, give another AAI dose.
- Don’t let your child stand up.
- Avoid activities like exercise, bathing, or alcohol consumption until fully recovered.
- Seek medical help, even if your child feels better.
Professor Adam Fox along with Dr Nandinee Patel, Dr Ru-Xin Foong, Dr Paul Turner, and Professor Graham Roberts, collaborated to produce a recently developed leaflet. Created in partnership with allergy charities and patient groups, the leaflet is designed to empower and support families, caregivers, grandparents, and anyone tasked with the care of individuals with food allergies.
This blog was written by Professor Adam Fox – November 2023. Professor Adam Fox can be found on Instagram @DrAdamFox – where you can follow his dedicated account for additional insights and advice on children’s allergies, designed to keep allergy families well-informed and aware.